Power Saving Mode Problem

On my desktop for quite some time now I have had a problem with it randomly going into power saving mode while I play Guild Wars(I haven't had any problems with other games). I have absolutely no idea as to why this is happening. My computer otherwise runs the game great. However, this one problem makes the game unplayable at times.

I've tried setting changing the power saving options so that It Never turns off the display and never puts the computer to sleep but to no avail. Has anyone had this problem before and/or knows whats going on? Is my computer overheating? Could my graphics card (GeForce 9600GT) be the problem?

Any help would be greatly appreciated. This problem is driving me crazy.

I think if it was overheating it would shut down, not change modes. You don't have any wonky third-party power software on there, do you? I know Toshiba loves to stick you with that kind of thing.

Is it possible you have a keyboard shortcut to change power modes that you're accidentally hitting?

You could try looking in the BIOS, there could be a Power Management setting there that needs to be changed.
I would also recommend checking for Registry Errors and updating all Drivers.

If it doesn't happen in other games, I would suspect either overheating, or a driver glitch/conflict.

For overheating, clean the dust out of the machine and check that ALL fans are running smoothly.

For drivers, make sure that your Windows and ALL drivers are up-to-date.

It would be helpful to have the full system specs and the temperatures attained while playing GW.

HWMonitor is an easy to use and free temperature monitoring program that I would recommend if you don't have something installed already.